This invention relates to an improved process, and the catalyst which achieves this process, for making ethylene glycol and methanol directly from synthesis gas, i.e., mixtures of hydrogen and carbon monoxide. More particularly, this invention achieves the production of ethylene glycol and methanol and derivatives thereof directly from synthesis gas in the presence of a cobalt catalyst and an organosilicon compound having a hydrogen bonded to silicon.
The reaction of carbon monoxide and hydrogen in the presence of a cobalt catalyst is disclosed in U.S. Pat. No. 2,636,046, filed Oct. 16, 1948. In this patent, Gresham describes the production of polyfunctional oxygen-containing organic products including such compounds as ethylene glycol, glycerine, and the like.
This is accomplished by the reaction of hydrogen with carbon monoxide in the presence of a solvent to produce glycol. According to this patent, the reaction of carbon monoxide with hydrogen must be at pressures of above 1,000 atmospheres and "particularly above a minimum of about 1,400 atmospheres" in order to obtain the "polyfunctional oxygen-containing organic compounds . . . in excellent yield" (column 2, lines 9-17). The patent specifically states at column 2, lines 37-43, that
"[I]n the hydrogenation of oxides of carbon at pressures of 1,000 atmospheres and below, virtually no polyfunctional compounds are produced. At pressures above 1,000 atmospheres and especially at pressures of about 1,500 to 5,000 atmospheres, preferably 2,000 to 5,000 atmospheres, polyfunctional compounds are obtained."
The examples of the patent describe the use only of cobalt catalysts although the patent indicates that the catalyst may contain "cobalt, ruthenium, etc."
Gresham et al., U.S. Pat. No. 2,534,018, describe a process for preparing ethylene glycol by reacting carbon monoxide and hydrogen using a cobalt halide catalyst at a pressure of 3000 atmospheres and a temperature of 275.degree. C. in a water/benzene solvent. Minor amounts of glycol formate were also reported.
Pruett and Walker, U.S. Pat. No. 3,833,634, patented Sept. 3, 1974, based on an application originally filed Dec. 21, 1971, describe a process for preparing glycols by reacting an oxide of carbon with hydrogen using a rhodium carbonyl complex catalyst. The examples of the patent compare the reaction of hydrogen and carbon monoxide in the presence of the desired rhodium containing catalyst and other metals. In Example 17 of the patent dicobalt octacarbonyl and acetic acid were charged to a reaction vessel and the reaction carried out. Traces of the mono- and diacetate of ethylene glycol were detected but no ethylene glycol was detected.
According to Roy L. Pruett, Annals, New York Academy of Sciences, Vol. 295, pages 239-248 (1977), at pages 245, metals other than rhodium were tested to determine the production of ethylene glycol from mixtures of carbon monoxide and hydrogen. These metals include cobalt, ruthenium, copper, manganese, iridium and platinum. Of these metals, only cobalt was found to have a slightly activity, citing British Pat. No. 665,698 which corresponds generally to U.S. Pat. No. 2,535,060. Pruett stated that such slight activity with cobalt was "qualitatively" in agreement with the results obtained by Ziesecke, 1952, Brennstoff-Chem, 33:385.
As pointed out above, ethylene glycol can be produced directly from a mixture of hydrogen and carbon monoxide using a rhodium carbonyl complex as a catalyst. There has been a substantial amount of work done on the formation of ethylene glycol from mixtures of hydrogen and carbon monoxide in the presence of rhodium carbonyl clusters. Such work is exemplified by the disclosures of U.S. Pat. Nos. 3,833,634; 3,878,214; and 3,878,290.
Further, the reaction of carbon monoxide and hydrogen in the presence of dioxane and a cobalt catalyst to give ethylene glycol was reported by H. M. Feder and J. S. Rathke, Ann. N.Y. Acad Sci., 333,45 (1980).
The preparation of glycol esters, such as ethylene glycol diesters, by the reaction of carbon monoxide and hydrogen in the presence of a ruthenium or osmium-containing catalyst and a liquid phase medium containing a carboxylic acid co-reactant is disclosed in U.S. Pat. No. 4,268,689, issued May 19, 1981. In comparative example XV of said patent the use of dicobalt octacarbonyl as the metal-containing catalyst formed methyl acetate (0.7 percent), ethyl acetate (2.7 percent), and glycol diacetate (0.1 percent). The process of U.S. Pat. No. 4,268,689 is carried out with a co-catalyst species selected from the group consisting of alkali metal salts, alkaline earth metal salts, quaternary ammonium salts, iminium salts and quaternary aliphatic phosphonium salts. The use of organosilicon compounds is not disclosed.
Several reports have been made wherein formaldehyde or CH.sub.2 O-containing compounds are reacted under a pressure of carbon monoxide and hydrogen in the presence of a cobalt catalyst to give glycolaldehyde, glycol, and their ethers. Exemplary of such reports are: J. A. Roth and M. Orchin, J. Organometal Chem., 172, C27 (1979), M. Muller-Cunradi, K. Pieroh, and L. Lorenz, German Pat. No. 890,945 (1953); K. Pieroh, German Pat. No. 875,802 (1953); U.S. Pat. No. 2,525,793 (1950) to W. F. Gresham and R. E. Brooks; U.S. Pat. No. 2,449,470 (1948) to W. F. Gresham and R. E. Brooks; U.S. Pat. No. 2,451,333 (1948) to W. F. Gresham and R. E. Brooks; K Hamada, K. Baba, and N. Hagihara, Osaka Univ. Inst. Sci. and Ind. Res. Mem., 14, 207 (1957); U.S. Pat. No. 4,079,085 (1978) to R. G. Wall; U.S. Pat. No. 3,920,753 to T. Yukawa and H. Wakamatsu; U.S. Pat. No. 4,071,568 to T. Onoda and S. Tomita; JA No. 51-128903 to T. Onada and S. Tomita; JA No. 52-73810 to T. Onoda and S. Tomita; JA No. 53-098917 (1978) to H. Shibata, S. Mori, Y. Ohkago, and T. Kameda; and H. M. Feder and J. S. Rathke, Ann. N.Y. Acad. Sci., 333,45 (1980). Unfortunately the aforementioned reactions require starting with formaldehyde or a CH.sub.2 O containing compound and not with carbon monoxide and hydrogen.
The reaction of aldehydes having the formula RCHO (wherein R is n-C.sub.3 H.sub.7, n-C.sub.6 H.sub.13 or c-C.sub.6 H.sub.11) with CH.sub.3 (C.sub.2 H.sub.5).sub.2 SiH to give the product: ##STR1## has been reported by S. Murai, T. Kato, N. Sonoda, Y. Seki, and K. Kawamoto, Abstr. A.C.S. Meeting, Honolulu, April 1979, No. 262; Agnew. Chem. International Ed., 18, 393 (1979). The reaction is carried out at room temperature under a pressure of 50 Kg/cm.sup.2 in the presence of carbon monoxide, dicobalt octacarbonyl, and triphenylphosphine. Similarly, the aforementioned reactants have been reported by Y. Seki, S. Murai, and N. Sonoda, Agnew. Chem. International Edit., 17, 119 (1978) to produce: ##STR2##
The high activity of cobalt as a catalyst in the present invention for the conversion of carbon monoxide and hydrogen to ethylene glycol and its derivatives as compared to the activity of cobalt reported earlier (see above) may be viewed in the light of a combination of the following: The reaction of Co.sub.2 (CO).sub.8 with R.sub.2 SiH.sub.2 (R=ethyl, phenyl) to produce (CO).sub.9 Co.sub.3 COSiR.sub.2 Co(CO).sub.4 has been reported [S. A. Fieldhouse, A. J. Cleland, B. H. Freeland, C. D. M. Mann, and R. J. O'Brien, J. Chem. Soc. (A), 2536 (1971)]; K. Tominaga, N. Yamagami, and H. Wakamatsu, Tet. Lett., 2217 (1970) and G. Fachinetti, U.S. application Ser. No. 12,612, commonly assigned, have reported that (CO).sub.9 Co.sub.3 C--Y reacts with carbon monoxide and hydrogen to give products having one carbon atom and one oxygen atom more than C--Y e.g., (CO).sub.9 Co.sub.3 C--OCH.sub.3 .fwdarw.HOCH.sub.2 CH.sub.2 OCH.sub.3 ; it has been reported [J. A. Gladysz, J. C. Selover, and C. E. Strouse, J. Am. Chem. Soc., 100, 6766 (1978)] that an alpha-trimethylsilyloxy substituent can accelerate carbonylation of an alkyl group.
In copending application U.S. Ser. No. 278,899, filed concurrently herewith, a process is disclosed for the manufacture of ethylene glycol, methanol, and derivatives thereof from the reaction of hydrogen and carbon monoxide by a homogeneous catalytic process using as the catalyst a ruthenium containing compound and an organosilicon compound having a hydrogen bonded to silicon (--Si--H).
In copending application U.S. Ser. No. 278,898, filed concurrently herewith is disclosed a process for the manufacture of alcohols and derivatives thereof from the carbon residue of an organosilicon compound wherein such alcohol has one carbon and one oxygen more than the corresponding carbon residue from which it was derived.
Owing to the reduced availability of petroleum sources the cost of producing chemicals from petroleum has been steadily increasing. Many have raised the dire prediction of significant oil shortages in the future. Obviously a different low cost source is needed which can be converted into the valuable chemicals now derived from petroleum sources. Synthesis gas is one such source which can be effectively utilized in certain circumstances to make chemicals.
The most desirable aspect of synthesis gas is that it can be produced from non-petroleum sources. Synthesis gas is derived by the combustion of any carbonaceous material including coal, or any organic material, such as hydrocarbons, carbohydrates and the like. Synthesis gas has for a long time been considered a desirable starting material for the manufacture of a variety of chemicals and, as discussed hereinabove, homogeneous cobalt-containing catalysts will produce ethylene glycol and methanol directly from synthesis gas.
However, while previously no processes using homogeneous cobalt catalysts will produce ethylene glycol and other polyhydric alcohols, generally very high pressure is required and it would be desirable to produce ethylene glycol and methanol or derivatives thereof at high process efficiency and low or moderate pressures.